USES OF THE FORESTS. 3 
USES OF THE FORESTS. 
I. Forests create or gradually but constantly improve a soil. 
The roots penetrate deeply into the ground, and thus let in the 
air to produce its slow but sure effects. The radicles decom- 
pose the grains of sand, and extract from them some of the 
elements essential to a soil; they drink in moisture and the 
carbonic acid which has been formed beneath, or brought down 
from the atmosphere above, the surface; and from these several 
elements, acted on by heat, light and air, in the leaves, and by 
that unknown influence, vegetable life, are formed the various 
substances which compose the plant. The annual deposit of 
leaves, and the final decay of the branches and trunk, go to 
constitute the mould upon which other plants grow. And the 
soil thus formed is kept by the thick matting of the roots from 
washing away. 
An unprotected hill soon loses its soil. Every rain bears 
away a portion, till it becomes a bare rock, and the slow pro- 
cess must recommence by which rock had been origmally con- 
verted into soul. That process takes place slowly on all uncov- 
ered rocks, but far more surely and rapidly under cover of 
trees. There also the invisible sporule, borne thither on the 
wind, perhaps, from a distant continent, attaches itself to the 
naked rock and vegetates; encrusting its surface with a lichen 
which gets thence a foothold and an alkali, while it lives on 
the atmosphere. From the thin layer left by its decay, another 
species springs, which in turn gives place to mosses and herba- 
ceous plants. Whoever has climbed Monument Mountain in 
Stockbridge, has had an opportunity of observing this process 
in its different stages and circumstances. On the projecting 
cliffs of white quartz, of which the mountain consists, the beau- 
tiful lichens which paint its sides have made no more progress 
than if the mountain had been thrown up two years ago. ‘They 
are spread upon it as thin as paper, and perfectly fresh. 
Wherever they decay, the violence of the rain and winds 
washes them clean off, and the work is begun each year anew. 
But in the protected crevices, and under shelter of the few trees 
